Go Fucking Do It - Set a deadline and a price. If you fail, you pay.
LogicLike - Improve logical thinking through engaging brain games
Publicly - Build in the open
Dualnback.works - Dual N-back is a specific brain training exercise, that's been shown by research - it might improve fluid intelligence.
Accountable Boss - Helping you reach your goals, as your boss
JobFlare - Brain games for job seekers